数码单反相机焦平面光电转换函数的测量及分析  

Measurement and analysis of the focal plane opto-electronic conversion functions for digital single lens reflex cameras

作　　者：吕玮阁[1] 冯珂 郑晓东[1] LYU Weige;FENG Ke;ZHENG Xiaodong(College of Optical Science and Engineering,Zhejiang University,Hangzhou 310027)

机构地区：[1]浙江大学光电科学与工程学院,浙江杭州310027

出　　处：《光学仪器》2023年第2期1-7,共7页Optical Instruments

基　　金：教育部光电教指分委2020年教育教学研究“双一流”项目(2020SYL34);2021年浙江省虚拟仿真实验教学项目(24)。

摘　　要：为了在光学实验中合理应用数字成像设备,需要获取并处理其物理输入量与数字输出量之间的关系。基于ISO 14524:2009标准,对数码单反相机Canon EOS 500D的焦平面光电转换函数进行了实验测量及数据分析。通过比较不同尺寸像素区域及不同图片格式对测量结果的影响,发现焦平面光电转换函数的测量偏差随像素区域尺寸的减小而增大,而RAW和JPEG两种文件格式的数字输出值与焦平面曝光量的关系分别为线性和非线性。当单反相机用作光分布记录测量的仪器时,采用直接反应传感器接收的辐照度信息的RAW格式作为输出数据,可以获得较大的动态范围,理论上可以避免相机非线性变换等后续处理带来的影响,经过必要的校正可以更精确地表示场景信息。It was necessary to obtain and process the relationship between the physical input and digital output of digital imaging equipment for its proper application in optical experiments.Based on ISO 14524:2009 standards,the focal plane opto-electronic conversion functions of digital single lens reflex camera Canon EOS 500D were measured and the data was analyzed.By comparing the effects of different pixel area sizes and different picture formats on the measurement results,it was found that the measurement deviation of the focal plane opto-electronic conversion function increased with the decrease of the pixel area size,and the relationship between the digital output value in RAW formats and the focal plane exposure was linear,which was different from the nonlinear relationship between the digital output value in JPEG formats and the focal plane exposure.When the DSLR camera was used as an instrument to record and measure light distribution,the RAW format that directly reflected the irradiance information received by the sensor can be used to obtain a large dynamic range,theoretically avoid the impact of subsequent processing of camera such as nonlinear transformation,and represent the scene information more accurately after necessary corrections.

关 键 词：光电转换函数 数码单反相机 相机原始数据 

分 类 号：O432[机械工程—光学工程] TB852.1[理学—光学] O439[理学—物理]